Many technologies place considerable emphasis on the effective management of energy consumption. For example, portable devices (such as mobile telephones and the like) use batteries that deliver a limited amount of power. These devices can benefit from energy management by reducing the frequency at which the devices require recharging. By contrast, data centers have an uninterrupted supply of power, but typically consume a large amount of power. These environments can benefit from energy management by reducing the costs associated with energy consumption.
To address these needs, the industry has developed numerous techniques to control the consumption of power. One type of technique operates by selectively shutting features of a system down. For example, the Partial Array Self Refresh (PASR) technique operates by refreshing only a portion of DRAM memory in a sleep mode of a device. The remaining portion of memory is unusable in this state. This approach is not fully satisfactory because it limits the functionality of the system while in a powered-down mode. Still other approaches have been proposed having associated shortcomings.